There are various held-held and manually operated devices for adjusting an orthodontic expander by turning or torquing the double-threaded expansion screw. All of these devices suffer from one or more disadvantages.
One disadvantage of some prior art devices results from the fact that the torquing device itself is small enough to fit entirely within the patient's mouth. This has a primary disadvantage of blocking off the dentist's view because the hand holding and operating the torquing device covers the patient's mouth, making it difficult to insert the device in the expansion screw. Secondly, the torquing device is so small that if the dentist inadvertently drops the device while it is in a patient's mouth, it could possibly be swallowed or cause discomfort to the patient since the patient is normally positioned with his or her mouth opening upwardly. Thus, the torquing device is typically placed on a tether for safety and comfort, making manipulation of the device even more cumbersome.
Many prior art devices which are capable of torquing an expansion screw are easily dislodged from the screw, either because it is difficult accurately to use the device through a full 90.degree. rotation of the screw as is required, or, as is equally common, while effecting a full quarter turn rotation of the expansion screw, the activating tip may slide out of the aperture in the center of the expansion screw in which the tip is received. In the case of an adjusting device becoming dislodged from the expansion screw while the dentist is turning the device, the pointed tip of the activating device has the potential to poke or scratch the tissue of the patient's mouth, causing discomfort or pain. Dentists, as well as patients, of course, are desirous of eliminating such discomfort.
Another disadvantage of some prior art devices is that they are difficult to operate in the sense that because of the structure of the device, the dentist's hand holding the device partially or substantially occludes the opening of the mouth. This restricts the amount of light that might enter the patient's mouth to illuminate the expander and adjusting mechanism, thereby rendering it more difficult to make an adjustment. Manipulating the small tool with the hand also restricts the field of vision of the dentist inside the patient's mouth.
These disadvantages are overcome by the improved device of the present invention.